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厦门西海域水体富营养化与赤潮关系的研究 总被引：18，自引：3，他引：18
本文根据1992～1993年的4个季节观测资料,对厦门西海域水体富营养化与赤潮关系进行了研究,结果表明同安湾、厦门西港、九龙江口均属于中营养海区,马銮湾、筼筜湖均属于过营养海区.同安湾、厦门西港、九龙江口浮游植物数量少,种类多,马銮湾、筼筜湖则相反.马銮湾扭曲小环藻、柔弱菱形藻形成了慢性赤潮.筼筜湖扭曲小环藻、骨条藻已形成了赤潮.马銮湾生态养殖,筼筜湖污水治理后,水质明显地得到改善,同时也减轻了厦门西港环境容量的负荷,1988年以来,厦门西港未再发生赤潮. 相似文献
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赤潮多发区塔玛亚历山大藻的麻痹性贝毒预警值研究 总被引：2，自引：0，他引：2
以厦门西海域养殖的翡翠贻贝为实验对象,在实验室内对塔玛亚历山大藻(Alexandrium tamarense(Lebour)Balech)采用单种培养技术,运用“麻痹性贝毒小白鼠生物检测法”进行毒性实验,研究了塔玛亚历山大藻对翡翠贻贝的麻痹性贝毒的毒力,藻密度为1×105个/dm3时,白鼠未死亡;藻密度为1×106个/dm3时,白鼠发生死亡.厦门西海域近年来暴发的赤潮一般起始于局部海区无害硅藻类浮游植物,在生态环境恶化下,硅藻类赤潮在生存竞争中消退,最终暴发有害赤潮.以试验结果为依据,根据厦门海域实际情况,参考各国贝毒临界值行动标准,提出适合南方赤潮多发区塔玛亚历山大藻的麻痹性贝毒藻密度预警值为1×105个/dm3. 相似文献
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围隔生态系中可溶性锰对两种形成赤潮藻类增殖的影响 总被引：6，自引：0，他引：6
1991年春秋两季,在厦门的临海陆基水池中进行了两次海洋生态系围隔实验,对海水中可溶性锰与赤潮发生规律大小的关系作探索性的研究。实验时人为地引发了中肋骨条藻(Skeletonema costatum,春)和颤藻(Oscillatoria,秋)的赤潮。实验用的厦门西海域海水,其可溶性锰含量在3～4μg/dm3的水平时,就足够藻类形成赤潮的增殖需求。若含量升高,在低于80μg/dm3情况下,过量的可溶性锰不影响浮游植物的数量和群落结构。但处于mg/dm3含量水平的可溶性锰,会影响浮游植物群落结构,浮游植物的数量也受到一定程度的抑制。 相似文献
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可溶性铁对某些硅藻赤潮生物增殖的影响 总被引：10，自引：1，他引：10
评述了在厦门进行的一次围隔实验结果。在同等富营养的各围隔桶中添加不同浓度的柠檬酸铁，研究可溶性铁对浮游植物的增殖效应。对结果回归分析表明：水体中可溶性铁的浓度与相应的叶绿素含量存在着明显的相关，且添加可溶性铁的围隔体内的细胞净增长速率快于同等富营养的天然海水。实验结果证明提高海水中可溶性铁浓度会促进某些硅藻（尤其是中肋骨条藻）的增殖。进而改变浮游植物的群落结构，引发硅藻赤潮并增大赤潮的规律。 相似文献
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文章通过2015年8月航次对厦门湾周边海域浮游植物群落结构特征以及相关环境因子进行调查。结果表明:调查共鉴定浮游植物2门25属41种,其中硅藻24属39种,甲藻1属2种,浮游植物细胞密度介于4.32×105~7.79×106个/m3。浮游植物的主要趋势是从九龙江口-厦门鼓浪屿海域向同安湾以及湾外递减,鼓浪屿海域属于高密度区域,这和营养盐的变化趋势基本相同。富营养化指数(E)平均为7.12,N/P值平均为17.36,说明水体呈富营养化,且营养盐结构表现为磷限制。根据研究结果显示,厦门湾近岸水体营养盐含量较高,浮游植物含量也较高,极容易引起赤潮,因此控制含氮磷污水的流入是改善水质状况的关键。 相似文献
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长江口区浮游植物营养限制因子的研究 Ⅱ.春季的营养限制情况 总被引：55，自引：7，他引：55
1999年5月在长江口及周围海域进行了环境调查,通过对该海域的浮游植物、叶绿素、营养盐、温度、盐度等进行分析,并结合现场实验和室内模拟实验,对本海域浮游植物的营养限制状况进行了研究.调查期间受冲淡水流量、流向和水体垂直分层的影响,冲淡水影响的范围和磷限制的范围相对于1998年11月均有所扩展.现场对26号站的加富实验直接证实了磷的限制作用;室内对26,41号站位的营养加富实验也均证实了磷限制的结论.根据浮游植物的需求和营养盐的补充情况,将该海区划分为:近河口区、冲淡区、台湾暖流影响区和黄海沿岸流影响区.本次调查处在春季水华的结束阶段,因而浮游植物的数量和种类数比1998年11月偏低. 相似文献
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Arne Schnack-Friedrichsen Angela M. Davis Jim D. Bennell Dei G. Huws 《Marine Georesources & Geotechnology》2001,19(4):221-243
The interdependence between the seismo-acoustic properties of a marine sediment and its geotechnical/physical parameters has been known for many years, and it has been postulated that this should allow the extraction of geotechnical information from seismic data. Though in the literature many correlations have been published for the surficial layer, there is a lack of information for greater sediment depths. In this article, a desktop study on a synthetic seafloor model illustrates how the application of published near-surface prediction equations to subsurface sediments (up to several tens of meters burial depth) can lead to spurious predictions. To test this further, acoustic and geotechnical properties were measured on a number of sediment core samples, some of which were subjected to loading in acoustically-equipped consolidation cells (oedometers) to simulate greater burial depth conditions. For low effective pressures (representing small burial depths extending to around 10 meters subsurface), the general applicability of established relationships was confirmed: the prediction of porosity, bulk density, and mean grain size from acoustic velocity and impedance appears generally possible for the investigated sedimentary environments. As effective pressure increases through, the observed relationships deviate more and more from the established ones for the near-surface area. For the samples tested in this study, in some instances increasing pressure even resulted in decreasing velocities. There are several possible explanations for this abnormal behavior, including the presence of gas, overconsolidation, or bimodal grain size distribution. The results indicate that an appropriate depth correction must be introduced into the published prediction equations in order to obtain reliable estimates of physical sediment properties for greater subsurface depths. 相似文献
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Shigehisa Nakamura 《Marine Geodesy》2000,23(1):55-61
Specific properties of the interannual sea level variations and annual tides in the Northwestern Pacific were studied. Several tide stations were monitored. The monthly mean sea level for the year of 1995 was analyzed at each tide station. A seismic event in 1995, some tectonic activity around the subject area, and the Kuroshio (the oceanic western boundary current) may possibly contaminate results which would have occurred from the astronomical annual tide alone. 相似文献
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The effect of different fixation and storage protocols on the flow cytometric (FCM) simultaneous analysis of bacterioplankton and phytoplankton in coastal seawater samples (Mediterranean coastal lagoons) was investigated. FCM measurements (cell number, fluorescence and scatter characteristics) were obtained through DAPI staining. Three fixatives [glutaraldehyde (GA), formaldehyde (FA) and paraformaldehyde (PFA)] and two storage (3 months duration) methods (5 °C and −196 °C) were tested. Two dominant populations were detected in studied samples: bacteria and eukaryotic picophytoplankton. Adding fixatives (2% final concentration) appears necessary to obtain FCM exhaustive counts of all the bacteria and phytoplanktonic cells. This was related to the permeation effect of fixatives which allowed a better DAPI staining of the cells. Maximum fluorescence, i.e. optimal staining of the cells was obtained with FA or PFA, and significant lower fluorescences with GA. Fixed samples stored at 5 °C induced rapid cell loss. Only storage in liquid nitrogen of samples fixed with FA or PFA, allows mid-term (≥4 months) preservation of bacteria or picophytoplankton cell numbers, and limited evolution of DAPI-induced fluorescence and scatter characteristics. 相似文献
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Coastal inundation associated with extreme sea levels is the main factor which leads to the loss of life and property whenever a severe tropical cyclonic storm hits the Indian coasts. The Andhra and Orissa coasts are most vulnerable for coastal inundation due to extreme rise in sea levels associated with tropical cyclones. Loss of life may be minimized if extreme sea levels and associated coastal flooding is predicted well in advance. Keeping this in view, location specific coastal inundation models are developed and applied for the Andhra and Orissa coasts of India. Several numerical experiments are carried out using the data of past severe cyclones that struck these regions. The simulated inland inundation distances are found to be in general agreement with the reported flooding. 相似文献
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《海洋学报(英文版)》2014,(9):F0003-F0003
<正>Acta Oceanologica Sinica(AOS)is a comprehensive academic journal edited by the Editorial Committee of Acta Oceanologica Sinica and is designed to provide a forum for important research papers of the marine scientific community which reflect the information on a worldwide basis.The journal publishes scholarly papers on marine science and technology,including physics,chemistry,biology, 相似文献
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Hoi-Soo Jung Kap-Sik Jeong Yong-Shik Chu Sung-Hyun Park Ki-Hyune Kim 《Marine Georesources & Geotechnology》2001,19(3):181-195
Grain size and water content in box-core sediments from the Clarion-Clipperton fracture zone (C-C zone) in the northeast equatorial Pacific were analyzed in detail to understand the downcore variations across a hiatus between Quaternary and Tertiary layers. Grain-size distributions in the topmost core sediments show two modes: a coarse mode (peaked at 50 μm) and a fine mode (at 2-25 μm). The coarse mode disappears gradually with depth accompanied by the dissolution of siliceous fossil tests, whereas the fine mode coarsens due to the formation of authigenic minerals. Water content increases abruptly across a color boundary between an upper pale brown layer and a lower dark brown layer that is the hiatus between Quaternary and Tertiary layers. Abundant smectites and microvoid molds, which are created by the prolonged fossil dissolution in the underlying sediment, are attributed for the abrupt downcore variation of water content. Overall variations in grain size and water content in the topmost core sediments in the western C-C zone are possibly constrained by the dissolution of biogenic siliceous fossils. Variations in geotechnical properties related to these changes must be considered in the design of nodule collectors. 相似文献
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Shigehisa Nakamura 《Marine Geodesy》2001,24(1):27-33
This article concerns an interrelation between the sea levels and the western boundary flow near a tectonic boundary in a local zone in the Northwestern Pacific. In this zone, sea level variations at stations located on the coast facing the Pacific are studied to find the interrelation between variations of the Kurosio flow as an index of the distance of the flow axis off a specific coast. The result is discussed after data processing of the monthly means of the sea levels, and a notice is taken of variations caused by active crustal upheavals during a seismic event, a local earthquake. 相似文献
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This study tests the hypothesis that the in situ void ratio of surficial marine sediments may be predicted from shear wave velocity-depth data with a reliability equal to that of other methods currently available. Shear wave velocity is fundamentally controlled by the number of grain-to-grain contacts per unit volume of material and by the effective stress across those contacts. In this study, three previously established empirical formulae are used to predict void ratio from velocity-depth data. Field data were acquired along a transect off the northern Californian coast across which water depth increased from 35 to 70 m and seafloor sediment type varied from sand to silty-sand, respectively. A towed seafloor sled device was used to collect shear wave refraction data, and a marked, systematic decrease in velocity was observed along the line, ranging from 35-70 m/s for the coarse, near-shore material to 25-40 m/s for the finer, offshore deposits. Void ratios predicted from these velocities were compared with data measured directly from box-core samples. Of the formulae used for prediction, two agree remarkably well with the control data. Both predicted and control values increase from 0.6-0.8 for the sandy material to 1.1-1.5 for the silty-sand. Thus, this study does not disprove the hypothesis set and demonstrates the potential of field shear wave velocity-depth data as a means of delineating spatial variation in void ratio for surficial marine sediments in a remote, nondestructive manner. 相似文献
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Particulate samples were collected from the Changjiang river system during a flood period, in May 1997, and POC, stable isotope and lipids associated with particles were examined. Results showed the decrease (0.84% ～ 1.88%) of organic carbon content from the upper reaches to the estuary.δ13C values of particulate organic carbon was in the range of -24.9×10-3 to -26.6×10-3, which were close to the isotopic signature of continental C3 vegetation. Total particulate n-alkanes concentrations varied from 1.4 to 10.1μg/dm3,or from 23.7 to 107μg/g of total suspended matter. Fatty acids were present in all the samples, from 1.4 to 5.4μg/dm3, with saturated and unsaturated straight-chain and branched compounds in the carbon number range from C12 to C30. Both δ13C and the ratio of carbon content to nitrogen content indicate the predominance of terrestrial inputs (soil organic matter) among the particles. The biomarker approach has been used to identify the relative portion of terrigenous and autochthonous fraction in the particulate samples. The distribution of fatty acids suggests a striking phytoplanktonic and microbial signal in most particle samples. The terrestrial alkanes are used to estimate the contribution of terrestrial inputs along the mainstream. 相似文献